Tag: zoology

Questions Related to zoology

Which one is not an enzyme of digestive system?

  1. Enterokinase

  2. Amylase

  3. Trypsin

  4. Enterogastrone


Correct Option: D
Explanation:

Enterogastrone is a hormone, whereas amylase, trypsin and enterokinase are enzymes. Amylase is starch splitting enzyme, while trypsin is a proteolytic enzyme. Enterokinase is a proteolytic enzyme, which acts on trypsinogen and converts it to active trypsin. Enterogastrone, is a hormone secreted by the duodenal mucosa, when fatty food is in the stomach or small intestine; it is also thought to be released, when sugars and proteins are in the intestine. Enterogastrone is transported by the bloodstream to the glands and muscles of the stomach, where it inhibits gastric movements and secretions, possibly by blocking the production or activity of gastrin, the hormone that initially causes these functions.

Secretin hormone is produced in

  1. Stomach and stimulates gastric glands

  2. Intestine and stimulates pancreatic glands

  3. Liver and stimulates gall bladder

  4. Intestine and stimulates crypts of Lieberkuhn


Correct Option: B
Explanation:

Secretin is the most important hormone of digestive tract and also first hormone discovered in digestive tract. This hormone stimulates pancreas for synthesis and secretion of non enzymatic part of pancreatic juice. It also stimulates liver for secretion of bile juice and inhibit the gastric acid secretion in stomach and reduce rate of contraction of stomach.

Secretion of gastric juice is controlled by

  1. Gastrin

  2. Chlolecystokinin

  3. Enterogastrone

  4. None of the above


Correct Option: A
Explanation:

As food enters the confined space of the stomach, it starts applying pressure to the stomach wall. As food enters the stomach, the food bangs against the stomach wall, distending it. This distention causes the stomach to release gastrin. Gastrin stimulates the gastric glands to secrete more gastric juice. 

Contraction of gall bladder is carried by

  1. Citric acid and acetyl Co-A

  2. Gastrin

  3. Cholecystokinin

  4. None of the above


Correct Option: C
Explanation:

Fatty acids in the lumen of the duodenum stimulate endocrine cells to release the hormone cholecystokinin (CCK). CCK stimulates contractions in the smooth muscle of the gallbladder. CCK causes relaxation of the sphincter of Oddi, allowing bile release into the duodenum.

Which of the following hormones help in contraction of gall bladder?

  1. Gastrin

  2. Secretin

  3. Cholecystokinin

  4. Insulin


Correct Option: C
Explanation:

Fatty acids in the lumen of the duodenum stimulate endocrine cells to release the hormone cholecystokinin (CCK). CCK stimulates contractions in the smooth muscle of the gallbladder. CCK causes relaxation of the sphincter of Oddi, allowing bile release into the duodenum.

Which part of body secretes the hormone secretin?

  1. Stomach

  2. Oesophagus

  3. Illeum

  4. Duodenum


Correct Option: D
Explanation:

When food leaves the stomach through its pyloric end and enters the duodenum it is called chyme (acidic). The $HCI$ of chyme stimulates the wall of duodenum to secrete hormones. It secretes various hormones, example secretin, which is the most important hormone of digestive tract and is released by duodenum. This hormone stimulates pancreas for synthesis and secretion of non enzymatic part of pancreatic juice. It also stimulates liver for secretion of bile juice and inhibit the gastric acid secretion in stomach and reduces rate of contraction of stomach.

The hormone 'secretin' stimulates secretion of

  1. Pancreatic juice

  2. Bile juice

  3. Salivary juice

  4. Gastric juice


Correct Option: A
Explanation:

Secretin is the most important hormone of digestive tract. This hormone stimulates pancreas for synthesis and secretion of non enzymatic part of pancreatic juice. It also stimulates liver for secretion of bile juice and inhibit the gastric acid secretion in stomach and reduce rate of contraction of stomach.

The function of enterogastrone hormone is

  1. To control excretion

  2. To inhibit gastric juice secretion

  3. Regulate the absorption of food

  4. To stimulate gastric glands to release gastric juice


Correct Option: B
Explanation:

Enterogastrone is a hormone secreted by the duodenal mucosa, when fatty food is in the stomach or small intestine; it is also released, when sugars and proteins are in the intestine. Enterogastrone is transported by the bloodstream to the glands and muscles of the stomach, where it inhibits gastric movements and secretions, by blocking the production or activity of gastrin.

First discovered hormone

  1. Thyroxine

  2. Adrenaline

  3. Secretin

  4. Insulin


Correct Option: C
Explanation:

Wm. M. Bayliss and Ernest H. Starling  discovered  secretin, the first hormone, in 1902. They discovered this hormone when they were studying the pancreatic secretion. Secretin hormone stimulates the pancreas to secrete digestive fluid.

Secretion of pancreatic juice is stimulated by

  1. Gastrin

  2. Secretin

  3. Enterogastrone

  4. Enterokinase


Correct Option: B
Explanation:

Secretin is the most important hormone of digestive tract. This hormone stimulates pancreas for synthesis and secretion of non enzymatic part of pancreatic juice, while pancreozymin promotes the secretion of enzymatic part of the pancreatic juice. Secretin also stimulates liver for secretion of bile juice and inhibit the gastric acid secretion in stomach and reduces rate of contraction of stomach.